The present invention relates to systems and methods for assisting deglutition, and more particularly to systems and methods for stimulating deglutition musculature in order to reduce effects of dysphagia.
The condition of having an inability to swallow is generally described as “dysphagia.” Dysphagia is commonly associated with ailments such as strokes, neurodegenerative diseases, brain tumors, respiratory disorders, and others. In some forms, dysphagia results in aspiration during “deglutition,” the act of swallowing. Aspiration during deglutition is of great concern as it increases the risk of aspiration pneumonia. In particular, there is evidence that aspiration pneumonia inflicts about a 20% death rate in the first year after a stroke and about a 10% to 15% death rate each year thereafter. Traditional treatments for dysphagia have employed either temporary feeding through a nasogastric tube or enteric feeding through a stoma to the stomach in chronic cases.
Techniques of electrical stimulation of electrically excitable tissue within the body of a living subject have been developed utilizing stimulating electrodes and a signal generator to supply electrical charges in a controlled or predetermined manner. PCT App. Pub. WO 2004/028433 (“Ludlow”) (entitled “Methods and Devices for Intramuscular Stimulation of Upper Airway and Swallowing Muscle Groups;” published Apr. 8, 2004) describes stimulation of muscles within a neck region of a human subject for the purpose of causing muscles to react as a swallowing effect. More specifically, Ludlow describes inducement of swallowing in a subject's body by implanting electrodes in two or more muscles of the upper airway musculature and connecting the electrodes with a signal generator that provides coordinated control signals. Other techniques and methods of artificial stimulation using transcutaneous, non-implanted systems are disclosed in U.S. Pat. Nos. 5,725,564; 5,891,185; 5,987,359; 6,104,958; and 6,198,970, all to Freed et al.